That's true but it's also true that studies like this one, which are true on average of the population, are often not true for each individual. It's worth pointing out that it doesn't apply to everyone.
Almost nothing is universal. You could have a study that says, "Falling out of an airplane from 30,000ft is deadly" and you can still find counterexamples. So I agree, it doesn't need to be explicitly stated at every turn.